Despite a burgeoning literature suggesting that social networks influence the health status, community care and utilization behavior of frail elders, little properly designed and conducted field research has addressed the issue. Part of the problem has been poor conceptualization of network structures and insufficient operationalized measures of dimensions of social support. A facilitating study by a Co-Investigator identified, defined and reliably measured 8 separate dimensions of social networks through a study of the elderly in Lowell, MA. Building upon this facilitating work, we propose to undertake a social/epidemiological investigation of the role of social networks in the community/home care of the frail elderly. There are major components (each with specific research questions): a) To explain the role of informal social networks in the provision of community care to frail elders; b) To identify and describe the relationship between social networks and a range of relevant socio-demographic variables (e.g. age, sex, SES, marital status, employment situation, degree of frailty, perceived health status, utilization behavior and geographic location). A geographically stratified random sample (n=5300) of the general population aged 70 years and over will be drawn from a 1983 computerized list of names and addresses (required of every citizen of Mass. by law) and screened for degree of frailty. Approximately 500 frail elders and 400 of their caregivers will be interviewed by telephone or in-person, if necessary, by trained interviewers. At least the following considerations motivate the proposed research: The magnitude of the elderly as a demographic category; The deleterious consequences for health of much nursing home care; The purported but fragmentary beneficial results of home/community care for the elderly; Conflicting claims concerning the cost-effectiveness of community/home care as compared with nursing home care; Renewed interest in the potential offered by studies of social networks.